Rachel Lucas has had one of those amazing cold turkey successes with addiction and credits attitude as a huge part of that success:
I suspect that applies to a whole lot of "pleasurable" things we human beings to do to ourselves that we know we shouldn't do but think we can't resist...After 20 years of serious addiction, all I had to do was decide that not smoking was a liberation rather than a punishment.
Just decide it. Not being able to have that cigarette isn’t something that sucks, it’s more like being slowly but surely released from prison.
And do read it all. There's much more to think about--she and her commenters have some great things to say.